El Forn landslide: an example of geological risk management in large sliding inhabited areas

(ENG) El Forn Landslide is one of the largest landslides in the Pyrenean area. To date, it has not been thoroughly studied or characterized by what is known of the existence of movements and their evolution (residual deformation, acceleration, more or less active areas, etc.). This paper presents the device implementation of a large active landslide inhabited from the Middle Ages, situated in the Andorran Pyrenees and its associated risk management. In 2000, the Govern d'Andorra initiated several actions to manage the risk associated with large slides, with an initial zoning of the territory in relation to different natural hazards (large landslides, rockfalls, debris flows and shallow landslides). In 2002 a map of buildability of the landslide was carried out, and in 2005 Andorran Government raised about the possibility of monitoring the most active areas of the slide. In 2007 work began on instrumentation that lasted until early 2009 in order to characterize the terrain (through surveys of 200 m deep) and placing measurement devices for monitoring all the slopes of El Forn Landslide. There are ongoing periodic readings of the instruments with the aim of identifying areas of greater movement and activity, but, given its characteristics (speed, size, etc.), it is not expected that one could get reliable results until a few years.